Use of an optical fiber for connection between an optical transmitter and an optical receiver reduces noise generation and facilitates signal transmission resistant to the influence of electromagnetic noise.
A light emitting device can be used as a source of the optical transmitter, and a plastic fiber can be used as an optical fiber. Then, by a simple configuration, it is possible to provide data transmission between electronic equipments, control of industrial equipments, and optical communication. In this case, for a transmission rate of 100 Mbps, the fall time to 10% of the peak value at the falling edge of the optical pulse is required to be e.g. 10 ns or less.
In general, in a light emitting device, the output optical signal lags behind the input electrical signal. For instance, even if the electrical signal starts to fall, the fall of the optical pulse lags due to carriers generated inside the light emitting device. This is called the tailing or skirting phenomenon. Pulse width distortion resulting from the tailing phenomenon degrades the transmission quality and makes it difficult to increase the transmission rate.